In order to maintain competitiveness of a 3rd generation mobile communication system in the field of communications, to provide a mobile communication service that is higher in rate, lower in delay and more personalized for a user, and to reduce an operation cost of an operator, a 3rd Generation Partnership Project (3GPP) standard working group is being devoted to research on an Evolved Packet System (EPS).
FIG. 1 is a structure diagram of access of a Universal Terrestrial Radio Access Network (UTRAN) to a Packet System (PS). As shown in FIG. 1, the whole PS may be divided into a 3rd Generation (3G) Radio Access Network (RAN) and a 3G Core Network (CN).
The 3G RAN may include a base station (e.g. a NodeB) and a 3G Radio Network Controller (RNC). The 3G RAN is mainly responsible for transmitting and receiving a radio signal, communicating with a terminal through an air interface, managing and scheduling radio resources of the air interface, and performing access control.
The 3G CN may include a Home Location Register (HLR), a Serving General Packet Radio Service (GPRS) Support Node (SGSN) and a Gateway GPRS Support Node (GGSN).
FIG. 2 is a structure diagram of access of an Evolved UTRAN (E-UTRAN) to an EPS. As shown in FIG. 2, the whole EPS may be divided into a 4th Generation (4G) RAN and a 4G CN.
The 4G RAN may include a base station, e.g., an evolved NodeB (eNodeB). The 4G RAN is mainly responsible for transmitting and receiving a radio signal, communicating with a terminal through an air interface, managing and scheduling radio resources of the air interface, and performing access control.
The 4G CN may include a Home Subscriber Server (HSS), a Mobility Management Entity (MME), a Serving Gateway (S-GW) and a Packet Data Network (PDN) Gateway (P-GW).
In the field of broadband communication, a Content Delivery Network (CDN) may be provided to cache contents at different places and orientate a user request for acquiring contents to a nearest cache server through a technology such as load balancing, thereby increasing a network access response speed of a user. The CDN may provide a service in response to a user request in a more efficient manner based on judgment of user proximity and server loads.
To fully utilize advantages of the CDN, a mobile network operator desires to deploy the CDN in a mobile network and to combine the CDN with the mobile network, thereby accelerating content delivery of a mobile user, increasing the response speed and saving bandwidths. The CDN may be deployed over a GGSN or a P-GW and may be naturally supported. However, a problem of deployment of the CDN at other positions of a mobile network, e.g., further sinking of a CDN to a radio network, has not been solved.
Any effective solution has not been proposed yet for a problem that a network element supporting both a network function of a CDN and a network function of a mobile network cannot be selected to process a packet data service in a current system.